System and method for conserving battery power in a mobile station

ABSTRACT

In one embodiment, a mobile station including a chassis having a display, a power reducer, a proximity sensor, and a microprocessor. The power reducer controls power consumption of the display. The proximity sensor is coupled to the chassis and causes the power consumption to be reduced when the display is within a predetermined range of an external object. The microprocessor is coupled to the proximity sensor and to the display and automatically activates the proximity sensor based on the mobile station receiving an incoming wireless telephone call.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/945,505, filed on Nov. 27, 2007, which is a continuation of U.S.application Ser. No. 11/516,316, filed on Sep. 6, 2007 (now issued asU.S. Pat. No. 7,319,889), which is a continuation of U.S. applicationSer. No. 10/463,630, filed on Jun. 17, 2003 (now issued as U.S. Pat. No.7,113,811), the teachings of all of which are incorporated herein byreference.

TECHNICAL FIELD OF THE INVENTION

The present invention is directed, in general, to mobile stations and,more specifically, to a mobile station of mobile radio system having areduced power consumption under certain operating conditions.

BACKGROUND OF THE INVENTION

Mobile stations have found many uses in today's world. When paired witha single base station located at a user's own premises, they are called“cordless telephones.” When they interact with various, geographicallydistributed cellular base stations, they are called “cellulartelephones” or simply “cell phones.”

Usually the stand-by time, as well as the talk-time, of a mobile stationdepend on the lifetime of a (rechargeable) battery inserted within themobile station and hence, on the load and/or on the capacity of thebattery.

Increasing of the capacity of the battery would increase the lifetime ofthe mobile station, but batteries having increased capacities are oftenlarger, heavier or more expensive, none of which are desirableattributes for a portable, affordable mobile station. Accordingly, whatis needed in the art is a way to prolong the lifetime of a mobilestation without having to use a battery with an increased capacity.

SUMMARY OF THE INVENTION

To address the above-discussed deficiencies of the prior art, thepresent invention provides a mobile station, including: (1) a chassishaving a display and (2) a proximity sensor coupled to the chassis andadapted to cause a power consumption of the display to be reduced whenthe display is within a predetermined range of an external object.

Thus, by reducing the power consumption of the display of an activatedtelephone set in case the display is not needed, i.e., in particularduring a telephone call, current is saved instead of needlessly consumedfrom the (rechargeable) battery. Accordingly, the spared availablebattery power may be significant, especially for color displays,resulting in an overall increasement of the stand-by and/or talk time ofthe telephone set.

According to preferred embodiments the means are adapted to switch-offthe display in response to a detection that the set, preferably thedisplay of the set, is attached near to an object, in particular to theear.

As a consequence, if a call for example is incoming for example,possibly the user wants to see by means of the display the number and/orthe stored name of the calling party. However, if the user wants toaccept the call and hence is attaching the telephone set to the ear, theinvention enables that the display is switched off. In a similar way, incase the user is trying to call a third party he may want to have a lookat the display for verifying the entered number, but when the call isestablished he is likewise attaching the set and accordingly the displayto his ear for performing the call. On the other hand, as long as thetelephone set is inside a pocket, for example, it is not necessary tokeep the display in an on-condition or to indicate the number and/or thename of a calling party.

Moreover, the means may be further adapted to switch-on the display inresponse to a detection that the set, preferably the display of the set,is moved away from any object, in particular from the ear.

As an alternative or in addition, the triggering event for currentsaving purposes may also be selectable by the user, for example via amenu list. According to further preferred refinements, the proximitysensor is proposed to be a heat flow or temperature sensor, an opticalor infrared sensor, or a load sensor. However, as a further advantage,basically any kind of proximity sensor which is capable of observing aclose range or small distance may be used.

Correspondingly, the invention proposes a method for saving availablebattery power of a mobile station, in particular of a mobile stationcomprising the steps of detecting an attachment of the set, inparticular of the display of said set near to an object, in particularto the ear, and switching off the display in response to such adetection in case the display is in an on-condition.

The foregoing has outlined, rather broadly, preferred and alternativefeatures of the present invention so that those skilled in the art maybetter understand the detailed description of the invention thatfollows. Additional features of the invention will be describedhereinafter that form the subject of the claims of the invention. Thoseskilled in the art should appreciate that they can readily use thedisclosed conception and specific embodiment as a basis for designing ormodifying other structures for carrying out the same purposes of thepresent invention. Those skilled in the art should also realize thatsuch equivalent constructions do not depart from the spirit and scope ofthe invention in its broadest form.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference isnow made to the following descriptions taken in conjunction with theaccompanying drawings, in which:

FIG. 1 schematically depicts a preferred embodiment of a mobile stationhaving the inventive detection functionality;

FIG. 2 schematically depicts a block diagram showing essentialcomponents of the invention;

FIG. 3 is a flow diagram of exemplary steps for reducing power to adisplay; and

FIG. 4 is a flow diagram of exemplary steps for automatically answeringan incoming call.

DETAILED DESCRIPTION

FIG. 1 illustrates a mobile station 110 of a mobile radiotelecommunication system having a loudspeaker 120 and a microphone 130.A proximity sensor 140 is located near a display 150 toward a side ofthe loudspeaker 120. A keypad 160 allows a user (not shown) to establishan outgoing call, accept an incoming call and/or terminate an activecall. However, it should be apparent to one skilled in the pertinentart, that these functionalities can be also performed by other controlmeans, for example by speech control. The proximity sensor 140 isintegrated within the mobile station 110 to enable a functionality asdescribed in more detail with regard to FIG. 2.

As can be seen from FIG. 2, an incoming call may be managed by a centralprocessing unit 220, for example for further specific processing. Forexample, the number or the name of the calling party stored within astorage (not referenced) implemented within the mobile station 110 canbe depicted at the display 150.

If the user of the mobile station 110 wants to accept the incoming call210, he may press a key on the keypad 160 or issue a voice command.Alternatively, an incoming call may directly activate the proximitysensor 140 without the necessity of pressing a key on the keypad 160 toaccept the call.

In response to the acceptance of the incoming call 210 or automatically,the proximity sensor 140 is activated to monitor a proximity 230 to anexternal object (not shown), for example a range of about fivecentimeters. This is preferably done by a standard low-cost proximitysensor, for example a thermal sensor. However, other proximity sensors,such as conventional mechanical proximity (load) sensors, opticalsensors or range detecting sensors, fall within the broad scope of thepresent invention. If the proximity sensor 140 detects an externalobject (such as the user's ear) within the monitored range, the powerconsumption of the display 150 is reduced, most preferably by switchingthe display 150 completely off, as indicated by an arrow 240, to sparebattery power during the telephone call.

When the telephone call 210 is finished, the user of the mobile station110 typically moves the mobile station 110 away from his ear. Thiscauses the proximity sensor 140 to move out of range of the externalobject (in this case the user's ear). Accordingly, in response thereto,the display 150 is switched back on, enabling the user to look atinformation on the display 150.

Correspondingly, for an outgoing call, the proximity sensor 140 isactivated by pressing a key on the keypad 160 to establish the outgoingcall to a third party. As long as the outgoing call remains in effectand the proximity sensor 140 detects proximity to an external object,e.g., the ear of the user, the display 150 remains in a state of reducedpower consumption, or off, as the case may be.

The function of switching the display off or on or otherwise reducingthe amount of power the display consumes may comprise hardware and/orsoftware components. For example, electronically readable instructionsexecutable in the central processing unit 220 may be stored on a memorychip located in the mobile station 110 and adapted to cooperate with theproximity sensor 140 to perform the function.

Moreover, if the proximity sensor 140 is directly activated by anincoming call or automatically activated, the display can be kept in aswitched-off condition as long as the mobile station 110 is, forexample, within a pocket (not referenced) or the like and is onlyswitched on when the user retrieves the mobile station 110 from thepocket to enable the user to look on the display 150 for an informationabout the calling party. If the user then wants to accept the call andthence places the mobile station 110 proximate an external object, suchas his ear, the proximity sensor 140 again detects an object, causingthe display again to be switched off.

FIG. 3 illustrates exemplary steps for reducing power to a display, asdescribed above, and FIG. 4 illustrates exemplary steps forautomatically answering an incoming call, as described above.

Although the present invention has been described in detail, thoseskilled in the art should understand that they can make various changes,substitutions and alterations herein without departing from the spiritand scope of the invention in its broadest form.

1. A mobile station, comprising: a display; a proximity sensor adapted to generate a signal indicative of the existence of a first condition, the first condition being that an external object is proximate; and a microprocessor adapted to: (a) determine, without using the proximity sensor, the existence of a second condition independent and different from the first condition, the second condition being that a user of the mobile station has issued a voice command to answer an incoming call; (b) in response to a determination in step (a) that the second condition exists, activate the proximity sensor; (c) receive the signal from the activated proximity sensor; and (d) reduce power to the display if the signal from the activated proximity sensor indicates that the first condition exists.
 2. The mobile station of claim 1, wherein the microprocessor is adapted to increase power to the display if the signal from the activated proximity sensor indicates that the first condition no longer exists.
 3. The mobile station as recited in claim 1, wherein the microprocessor reduces power to the display by turning off the display.
 4. The mobile station as recited in claim 1, wherein the proximity sensor is a mechanical proximity sensor, an optical sensor, or a range-detecting sensor.
 5. The mobile station as recited in claim 1, wherein the proximity sensor is located proximate to the display.
 6. A method of conserving battery power in a mobile station, the mobile station adapted to detect the existence of a proximity condition, the proximity condition being that an external object is proximate, the method comprising: the mobile station detecting the existence of an answered-call condition independent and different from the proximity condition, the answered-call condition being that a user of the mobile station has issued a voice command to answer an incoming call; the mobile station activating the proximity sensor in response to a determination that an answered-call condition exists; and the mobile station reducing power consumption of a display of the mobile station if the activated proximity sensor indicates that the proximity condition exists.
 7. The method of claim 6, further comprising the mobile station increasing power consumption of the display if the signal from the activated proximity sensor indicates that the proximity condition no longer exists.
 8. The method of claim 6, wherein reducing power consumption of the display comprises turning off the display.
 9. The method as recited in claim 6, wherein the detecting of the proximity of the external object is performed by a mechanical proximity sensor, an optical sensor, or a range-detecting sensor.
 10. A mobile station, comprising: a display; a proximity sensor adapted to generate a signal indicative of the existence of a first condition, the first condition being that an external object is proximate; and a microprocessor adapted to: (a) determine, independently of the determination whether the external object is proximate, the existence of a second condition different from the first condition, the second condition being that a user of the mobile station has issued a voice command to answer an incoming call; (b) in response to a determination in step (a) that the second condition exists, activate the proximity sensor; (c) receive the signal from the activated proximity sensor; and (d) reduce power to the display if the signal from the activated proximity sensor indicates that the first condition exists.
 11. The mobile station of claim 10, wherein the microprocessor is adapted to increase power to the display if the signal from the activated proximity sensor indicates that the first condition no longer exists.
 12. The mobile station as recited in claim 10, wherein the microprocessor reduces power to the display by turning off the display.
 13. The mobile station as recited in claim 10, wherein the proximity sensor is a mechanical proximity sensor, an optical sensor, or a range-detecting sensor.
 14. The mobile station as recited in claim 10, wherein the proximity sensor is located proximate to the display. 